/**
 * Created by eva on 2020/1/1.
 */
function Wave() {
    this.x = [];
    this.y = [];
    this.alive = [];
    this.r = [];
    this.num = 10;
}
Wave.prototype = {
    init : function () {
        for(var i = 0; i < this.num; i++){
            this.alive[i] = false;
            this.r[i] = 0;
        }
    },
    draw : function () {
        ctx1.save();
        ctx1.lineWidth = 2;
        ctx1.shadowBlur = 10;
        ctx1.shadowColor = "white";
        for(var i = 0; i < this.num; i++){
            if(this.alive[i]){
                this.r[i] += deltaTime*0.02;
                if(this.r[i] > 50){
                    this.alive[i] = false;
                    break;
                }
                var alpha = 1- this.r[i]/50;
                //draw
                ctx1.beginPath();
                ctx1.arc(this.x[i],this.y[i],this.r[i],0,Math.PI*2);
                ctx1.strokeStyle = "rgba(255,255,255,"+alpha+")";
                ctx1.stroke();
                ctx1.closePath();
            }
        }
        ctx1.restore();
    },
    born : function (x,y) {
        for(var i = 0; i < this.num; i++){
            if(!this.alive[i]){
                this.alive[i] = true;
                this.r[i] = 10;
                this.x[i] = x;
                this.y[i] = y;
                break;
            }
        }
    }

}